Method of manufacturing light emitting device and light emitting device

ABSTRACT

A method of manufacturing a light emitting device includes: mounting a light emitting element in a package in which a recess is defined, the light emitting element being mounted on a bottom surface defining the recess; forming a first reflecting layer by covering lateral surfaces defining the recess with a first resin containing a first reflecting material; forming a second reflecting layer covering the bottom surface defining the recess, wherein the step of forming the second reflecting layer comprises settling the second reflecting material in the second resin by a centrifugal force so as to form (i) a layer containing a second reflecting material on the bottom surface defining the recess, and (ii) a light-transmissive layer above the layer containing the second reflecting material; and disposing a phosphor-containing layer on the second reflecting layer and the light emitting element, the phosphor-containing layer comprising a third resin that contains a phosphor.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No.2018-124545 filed on Jun. 29, 2018, and Japanese Patent Application No.2019-055625 filed on Mar. 22, 2019, the disclosures of which are herebyincorporated by reference in their entireties.

BACKGROUND

The present disclosure relates to a method of manufacturing lightemitting device and a light emitting device.

A light emitting device in which a light emitting element is mounted onthe bottom surface of a recessed package has been known. For example,Japanese Patent Application Publication No. 2016-72412 discloses a lightemitting device in which a light emitting element is mounted on thebottom surface of a recess of a package, the bottom surface and thelateral surfaces of the recess are covered with a first resin layercontaining a reflecting material, and the reflecting material islocalized near the bottom surface and the lateral surfaces of therecess, and a method of manufacturing the same.

SUMMARY

The above patent publication discloses the method of disposing the layercontaining a reflecting material near the bottom surface and the lateralsurfaces of the recess by injecting a first resin containing thereflecting material into the recess, followed by applying a centrifugalforce to the first resin. At this time, the placement of the reflectingmaterial layer is accomplished by, for example, applying a centrifugalforce about an axis of rotation with the bottom surface of the recesspositioned outward of the axis, and then applying a centrifugal forceabout an axis of rotation with the lateral surfaces positioned outwardof the axis.

However, the techniques described above require high precisionadjustment in settling the reflecting material, and there is apossibility that the reflecting material layer is not continuouslydisposed from the bottom surface to the upper edges of the lateralsurfaces of the recess. Although the light emitting device disclosed inthe above patent publication can have high emission efficiency, thereremains room for further improvement.

Certain embodiments of the present disclosure are intended to providemethods of manufacturing light emitting devices having high emissionefficiency, and light emitting devices having high emission efficiency.

According to one embodiment, a method of manufacturing a light emittingdevice includes: mounting a light emitting element in a package on whicha recess is defined, the light emitting element being mounted on abottom surface in the recess; forming a first reflecting layer bycovering lateral surfaces of the recess with a first resin containing afirst reflecting material; forming a second reflecting layer by coveringthe bottom surface in the recess with a second resin containing a secondreflecting material so as to be in contact with the first reflectinglayer; and disposing a phosphor-containing layer, in which a third resincontains a phosphor, on the second reflecting layer and the lightemitting element. In the step of forming a second reflecting layer, alayer containing the second reflecting material and a light-transmissivelayer are formed on the bottom surface in the recess in that order bysettling the second reflecting material in the second resin by acentrifugal force while forming the second reflecting layer such thatthe layer containing the second reflecting material does not face atleast a portion of the lateral surfaces of the light emitting element.

According to another embodiment, a method of manufacturing a lightemitting device includes: mounting a light emitting element in a packageon which a recess is defined, the light emitting element being mountedon a bottom surface in the recess; forming a first reflecting layer bycovering lateral surfaces of the recess with a first resin containing afirst reflecting material; forming a second reflecting layer by coveringthe bottom surface in the recess with a second resin containing a secondreflecting material so as to be in contact with the first reflectinglayer; and disposing a phosphor-containing layer, in which a third resincontains a phosphor, on the second reflecting layer and the lightemitting element. The step of forming a second reflecting layerincludes: disposing the second resin on the bottom surface in the recesswhile being positioned between the lateral surfaces of the recess andthe light emitting element by potting; changing a shape of the secondresin so as to entirely cover the bottom surface in the recess exposedfrom the first reflecting layer by applying a centrifugal force to thepackage about an axis of rotation in which the bottom surface in therecess is positioned outside with respect to the axis of rotation; andcuring the second resin while applying the centrifugal force.

According to another embodiment, a light emitting device includes: apackage on which a recess is defined; a light emitting element mountedon a bottom surface in the recess; a first reflecting layer formed usinga first resin containing a first reflecting member, the first reflectinglayer covering lateral surfaces of the recess; a second reflecting layerformed using a second resin containing a second reflecting member, thesecond reflecting layer covering the bottom surface in the recess so asto be in contact with the first reflecting layer; and aphosphor-containing layer formed using a third resin containing aphosphor, the phosphor-containing layer disposed on the secondreflecting layer and the light emitting element. The first reflectinglayer has a configuration in which the first reflecting material isdispersed in the first resin. The second reflecting layer includes alayer containing the second reflecting material and a light-transmissivelayer disposed on the bottom surface in the recess in that order suchthat the layer containing the second reflecting material does not faceat least a portion of the lateral surfaces of the light emittingelement.

A method of manufacturing a light emitting device according toembodiments of the present disclosure can manufacture a light emittingdevice having high emission efficiency.

A light emitting device according to embodiments of the presentdisclosure has high emission efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic perspective view of the structure of a lightemitting device according to certain embodiments.

FIG. 1B is a schematic cross-sectional view taken along line IB-IB inFIG. 1A.

FIG. 1C is a schematic cross-sectional view of a portion of thestructure of the light emitting device according to the embodiment.

FIG. 2 is a flowchart of a method of manufacturing the light emittingdevice according to certain embodiments.

FIG. 3A is a schematic cross-sectional illustration of a step ofmounting a light emitting element in the method of manufacturing thelight emitting device according to the embodiment.

FIG. 3B is a schematic cross-sectional illustration of a step of forminga first reflecting layer in the method of manufacturing the lightemitting device according to the embodiment.

FIG. 3C is a schematic top-view illustration of the step of forming thefirst reflecting layer in the method of manufacturing the light emittingdevice according to the embodiment.

FIG. 3D is a schematic cross-sectional illustration of the step offorming a second reflecting layer in the method for manufacturing thelight emitting device according to the embodiment, which schematicallyshows the application of a centrifugal force to settle the secondreflecting material in the second resin that covers the bottom surfacein the recess of the package.

FIG. 3E is a schematic cross-sectional illustration of a step of forminga second reflecting layer in the method of manufacturing the lightemitting device according to the embodiment, which shows the state aftersettling the second reflecting material by a centrifugal force.

FIG. 3F is a schematic cross-sectional illustration of a step of formingthe phosphor-containing layer in the method of manufacturing a lightemitting device according to the embodiment.

FIG. 4 is a schematic cross-sectional view of the structure of a lightemitting device according to another embodiment.

FIG. 5 is a schematic cross-sectional view of the structure of a lightemitting device according to still another embodiment.

FIG. 6 is a schematic cross-sectional view of the structure of a lightemitting device according to still another embodiment.

FIG. 7A is a schematic perspective view of the structure of a lightemitting device according to still another embodiment.

FIG. 7B is a schematic cross-sectional view taken along line VIIB-VIIBin FIG. 7A.

FIG. 8A is a schematic top view of a light emitting device according tostill another embodiment.

FIG. 8B is a schematic cross-sectional view taken along line VIIIB-VIIIBin FIG. 8A.

FIG. 8C is a schematic cross-sectional vies taken along line VIIIC-VIIICin FIG. 8A.

FIG. 9A is a schematic top view of a light emitting device according tostill another embodiment.

FIG. 9B is a schematic cross-sectional view taken along line IXB-IXB inFIG. 9A.

DETAILED DESCRIPTION

Certain embodiments of the present disclosure will be explained belowwith reference to the drawings. The embodiments described belowexemplify a method of manufacturing a light emitting device, and a lightemitting device, in order to give shape to the technical ideas of thepresent disclosure, and are not intended to limit the present invention.The sizes, materials, shapes, and relative positions of the elementsshown merely exemplify these elements, and are not intended to limit thescope of the present invention unless otherwise specifically noted. Thesizes, the positional relationship, and the like shown in each drawingmight be exaggerated for clarity of explanation.

FIG. 1A is a schematic perspective view of the structure of a lightemitting device according to one embodiment. FIG. 1B is a schematiccross-sectional view taken along line IB-IB in FIG. 1A. FIG. 1C is aschematic cross-sectional view of a portion of the structure of thelight emitting device according to the embodiment.

Light Emitting Device

The light emitting device 100 includes a package 10 in which a recess 15is defined, a light emitting element 20 mounted on the bottom surface inthe recess 15, a first reflecting layer 30 formed by covering thelateral surfaces in the recess 15, a second reflecting layer 40 formedby covering the bottom surface in the recess 15 while being in contactwith the first reflecting layer 30, and a phosphor-containing layer 50containing a phosphor 51 disposed on the second reflecting layer 40 andthe light emitting element 20.

The package 10 includes an insulating substrate 2, first wiring portions3 positioned on the upper surface of a base portion 2 a of theinsulating substrate 2, second wiring portions 5 positioned on the lowersurface of the base portion 2 a, third wiring portions 6 positioned onthe lateral surfaces of the base portion 2 a, and vias 4 forrespectively electrically connecting the first wiring portions 3 and thesecond wiring portions 5. The package 10 is substantially rectangular inshape in a top view in which the recess 15 is formed. The opening of therecess 15 is substantially a rectangular shape in a top view.

The insulating substrate 2 includes the base portion 2 a above which thelight emitting element 20 is mounted, a first wall 2 b formed above theperimeter of the upper surface of the base portion 2 a, and a secondwall 2 c stacked on the first wall 2 b. The insulating substrate 2 has arecessed shape having an opening in the center inwards of the first wall2 b and the second wall 2 c.

The base portion 2 a, the first wall 2 b, and the second wall 2 c areformed such that they are stepped inwards thereof. The outer lateralsurfaces of the first wall 2 b and the outer lateral surfaces of thesecond wall 2 c are coplanar. The inner lateral surfaces of the firstwall 2 b are formed inwards of the inner lateral surfaces of the secondwall 2 c. The first wall 2 b positioned inwards of the second wall 2 ccan allow a first reflecting layer 30 to have an inclined surfacedescribed later. The lateral surfaces in the recess 15 may be inclinedsurfaces whose widths in a lateral direction increase from the bottomsurface to the opening, instead of the stepped shape.

Example materials of the insulating substrate 2 include: a thermoplasticresin, such as polyphthalamide (PPA), polyphenylene sulfide (PPS),liquid crystal polymer, and the like; or a thermosetting resin, such asan epoxy resin, silicone resin, modified epoxy resin, urethane resin,phenol resin, and the like. It is preferable to use a glass epoxy resin,ceramic, glass, or the like for the insulating substrate 2. In the caseof using a ceramic for the insulating substrate 2, it is particularlypreferable to use alumina, aluminum nitride, mullite, silicon carbide,silicon nitride, or the like.

The first wiring portions 3 are provided on the upper surface of thebase portion 2 a and to be electrically connected to the light emittingelement 20. The first wiring portions 3 include a first lead 3 a and asecond lead 3 b as a pair of positive and negative electrodes, and thelight emitting element 20 is flip-chip mounted on the first lead 3 a andthe second lead 3 b.

The second wiring portions 5 that are disposed on the lower surface ofthe base portion 2 a to serve as the external electrodes of the lightemitting device 100 are be electrically connected to an external powersource.

The vias 4 are provided in through holes passing through the baseportion 2 a, and the third wiring portions 6 are provided on the lateralsurfaces of the base portion 2 a, to electrically connect the firstwiring portions 3 and the second wiring portions 5. Either the vias 4 orthe third wiring portions 6 may be omitted as long as the first wiringportions 3 and the second wiring portions are electrically connected.

For the first wiring portions 3, the second wiring portions 5, and thethird wiring portions 6, for example, Fe, Cu, Ni, Al, Ag, Au, or analloy containing one of these can be used.

For the first wiring portions 3, the second wiring portions 5, and thethird wiring portions 6 may have a plated layer 7 formed on theirsurfaces. For the plated layer 7, for example, Au, Ag, Cu, Pt, or analloy containing one of these can be used. Using these materials for theplated layer 7 can further increase the effectiveness in reflecting thelight from the light emitting element 20.

The light emitting element 20 includes a light-transmissive substrate 21and a semiconductor layer 22 formed on the substrate 21. The substrate12 can be formed using a conductive material or an insulating material.Shape, size, and the like can be appropriately selected for the lightemitting element 20. As to the emission color of the light emittingelement 20, appropriately selected wavelength can be selected inaccordance with the application. For example, a GaN-based or InGaN-basedelement can be used as a blue light emitting element 20 (i.e.,wavelength of 430 to 490 nm). For an InGaN-based element,In_(X)Al_(Y)Ga_(1-X-YN) (0≤X≤1, 0≤Y≤1, X+Y≤1) or the like can be used.

The thickness of the light emitting element 20 (e.g., the height fromthe lower surface of the semiconductor layer 22 to the upper surface ofthe substrate 21) is in the range of, for example, from 100 μm to 300μm.

The first reflecting layer 30 and the second reflecting layer 40 reflectthe emitted light from the light emitting element 20.

The interior surfaces, more preferably the entire interior surfaces, ofthe recess 15 are preferably covered with the first reflecting layer 30and the second reflecting layer 40 such that the light emitted from thelight emitting element 20 is less likely to transmit through or beabsorbed by the bottom surface and lateral surfaces in the recess 15.Moreover, the surfaces of the light emitting element 20 are preferablyexposed from the first reflecting layer 30 and the second reflectinglayer 40 such that the upper surface and the lateral surfaces of thelight emitting element 20 are not covered with the first reflectinglayer 30 or the second reflecting layer 40 such that the extraction ofthe light emitted from the light emitting element 20 is not interfered.

The first reflecting layer 30 is formed to cover the lateral surfaces inthe recess 15 of the package 10 using a first resin containing a firstreflecting material 31. The first reflecting layer 30 covers the outeredges of the bottom surface in the recess 15 spaced apart from thelateral surfaces of the light emitting element 20. The first reflectinglayer 30 continuously covers from the outer edges of the bottom surfacein the recess 15 to the lateral surfaces in the recess 15. It is morepreferable for the first reflecting layer 30 to cover substantially theentire lateral surfaces in the recess 15, but is preferable to cover thelateral surfaces in the recess 15 such that the upper edge of the firstreflecting layer 30 is higher than the upper surface of the lightemitting element 20 in a cross-sectional view of the light emittingdevice 100.

The first reflecting layer 30 has a structure in which the firstreflecting material 31 is dispersed in the first resin. In the presentdisclosure, “the first reflecting material 31 dispersed in the firstresin” simply means that the reflecting material is dispersed enough tofunction as a reflecting layer, for example, a dispersed stateachievable by applying a resin containing a reflecting material by knownmethods in the art. The first reflecting layer 30 may contain the firstreflecting material 31 localized in one portion as long as it canfunction as a reflecting layer.

The concentration of the first reflecting material 31 contained in thefirst reflecting layer 30 is in the range of, for example, from 10 masspercent to 50 mass percent.

Covering the lateral surfaces in the recess 15 with the first reflectinglayer 30 can prevent or discourage the lateral surfaces in the recess 15from transmitting or absorbing light.

The second reflecting layer 40 is formed to cover the bottom surface inthe recess 15 of the package 10 using a second resin containing a secondreflecting material 41 while being in contact with the first reflectinglayer 30. The second reflecting layer 40 covers a portion of the firstreflecting layer 30 in addition to covering the upper surface of thebase portion 2 a of the insulating substrate 2 and the first wiringportions 3 at the bottom surface in the recess 15. The second reflectinglayer 40 covers the bottom surface in the recess 15 with a substantiallyuniform thickness.

Covering the bottom surface in the recess 15 with the second reflectinglayer 40 can prevent or discourage the plated layer 7 and the baseportion 2 a from transmitting or absorbing light.

The second reflecting layer 40 is disposed such that at lease someportions of the lateral surfaces of the light emitting element 20 areexposed from the second reflecting layer 40. In the present disclosure,only the portions of the lateral surfaces of the light emitting element20 located on the semiconductor layer 22 side, in other words, on thebottom surface side in the recess 15, are covered by the secondreflecting layer 40, and the other portions of the lateral surfaces,which are exposed from the second reflecting layer 40, are covered bythe phosphor-containing layer 50.

The lateral surfaces of the light emitting element 20 here refer to boththe lateral surfaces of the substrate 21 and the lateral surfaces of thesemiconductor layer 22.

In a cross-sectional view, the second reflecting material 41 in thesecond reflecting layer 40 is localized on the bottom surface side.

The second reflecting layer 40 preferably includes a layer 40 acontaining the second reflecting material 41 and a light-transmissivelayer 40 b, successively from the bottom surface in the recess 15. Thereflective-material-containing layer 40 a is created by settling thesecond reflecting material 41, which is the portion where the secondreflecting material 41 is disposed in high concentration in thedirection of depth of the second reflecting layer 40. Thelight-transmissive layer 40 b primarily containing a resin is an upperpart of the second reflecting layer 40 formed as a result of settlingthe second reflecting material 41. That is, there is no clear interfacecreated between the reflective-material-containing layer 40 a and thelight-transmissive layer 40 b.

The second reflecting layer 40 is disposed such that at least someportions of the lateral surfaces of the light emitting element 20 do notoppose the reflecting-material-containing layer 40 a. The secondreflecting layer 40 is preferably disposed such that substantially theentire lateral surfaces of the light emitting element 20 do not face thereflecting-material-containing layer 40 a. That is, it is preferablethat substantially the entire lateral surfaces of the light emittingelement 20 are not covered with the layer 40 a. In the presentembodiment, only some areas of the lateral surfaces of the lightemitting element 20 on the mounting surface side are covered with thereflecting-material-containing layer 40 a, while the remaining lateralsurface areas exposed from the reflecting-material-containing layer 40 aare covered with the light-transmissive layer 40 b or thephosphor-containing layer 50. In the present embodiment, with regard tothe lateral faces of the light emitting element 20, the secondreflecting layer 40 is disposed such that thereflecting-material-containing layer 40 a does not cover the entirelateral surfaces of the semiconductor layer 22.

Disposing the second reflecting layer such that at least some portionsof the lateral areas of the semiconductor layer 22 of the light emitting20 does not face the reflecting-material-containing layer 40 a canincrease the efficiency of extracting light from the lateral surfaces ofthe light emitting element 20, thereby improving the color distributionof light emitted from in lateral directions relative to the lightemitting element 20.

The second reflecting layer 40 can simply be disposed such that at leastsome portions of the lateral surfaces of the light emitting element 20do not face the reflecting-material-containing layer 40 a. However, inorder to further improve the effects described above, it is preferableto reduce the lateral surface areas of the light emitting element 20that oppose the reflecting-material-containing layer 40 a to the extentpossible. It is more preferable to have no lateral surface areas of thelight emitting element 20 that oppose the reflecting-material-containinglayer 40 a (see FIGS. 4 and 5).

Disposing the second reflecting layer 40 such that at least someportions of the lateral surfaces of the light emitting element 20 do notface the reflecting-material-containing layer 40 a means that the secondreflecting layer 40 is disposed such that at least one portion of eachof all lateral surfaces of the light emitting element 20 does not facethe reflecting-material-containing layer 40 a.

The thickness of the second reflecting layer 40 preferably is in therange of, for example, from 10 μm to 200 μm. Having a thickness of 10 μmor larger can facilitate the formation of the second reflecting layer40. A thickness of 200 μm at most can further improve the effectachieved by disposing the reflecting-material-containing layer 40 a soas to not face at least some portions of the lateral surfaces of thelight emitting element 20 described above.

By setting the thickness of the second reflecting layer 40 in the rangeof, for example, from 10 μm to 200 μm, the second reflecting layer 40can be disposed while reducing surface tension-induced creeping up ofthe resin onto the lateral surfaces of the light emitting element 20during the step of settling the second reflecting material 41 by acentrifugal force. Setting the thickness of the second reflecting layer40 smaller than the thickness of the bonding members, such as bumps,between the light emitting element 20 and the insulating substrate 2 canfurther improve the effect achieved by disposing thereflecting-material-containing layer 40 a so as to not face the lateralsurfaces of the light emitting element 20 discussed earlier.

The thickness of the reflecting-material-containing layer 40 a in thesecond reflecting layer 40 preferably is in the range of from 10% to100%, more preferably from 25% to 50%, of the thickness of the secondreflecting layer 40.

The concentration of the second reflecting material 41 in thereflecting-material-containing layer 40 a can be increased as thethickness percentage of the reflecting-material-containing layer 40 a inthe second reflecting layer 40 decreases. The concentration of thesecond reflecting material 41 in the reflecting-material-containinglayer 40 a is preferably higher than the concentration of the firstreflecting material 31 in the first reflecting layer 30. The secondreflecting layer 40 is preferably thinner in order to expose the lateralsurfaces of the light emitting element 20. For this purpose, increasingthe concentration of the second reflecting material 41 in thereflecting-material-containing layer 40 a can improve the lightextraction efficiency achieved by exposing the lateral surfaces of thelight emitting element 20, as well as reducing the transmission andabsorption of light by the bottom surface in the recess 15. Theconcentration of the second reflecting material 41 in thereflecting-material-containing layer 40 a can be set in the range of,for example, from 50 mass percent to 70 mass present.

In the case in which portions of the lateral surfaces of the lightemitting element 20 face the reflecting-material-containing layer 40 a,the thickness of the reflecting-material-containing layer 40 a ispreferably ¼ at most, more preferably ⅙ at most, even more preferably ⅛at most of the height of the lateral surfaces of the light emittingelement 20.

Examples of resin materials used for the first resin and the secondresin include thermosetting resins, such as an epoxy resin, modifiedepoxy resin, silicone resin, modified silicone resin, and the like.

The first resin and the second resin may be formed using the same resinmaterial, or different resin materials.

The viscosity of the second resin preferably is in the range of from 0.3Pa·s to 15 Pa-s at room temperature (20±5° C.). A viscosity of 0.3 Pa·sor higher facilitates the provision of the second resin on the bottomsurface in the recess 15 by potting. Using a second resin having aviscosity of 15 Pa·s at most facilitates change of its shape andsettlement of the second reflecting material 41 by a centrifugal force.The viscosity of the second resin for achieving the above describedeffects more preferably ranges from 0.5 Pa·s to 6 Pa·s.

The viscosity of the second resin in the present embodiment is theviscosity in the state of containing a second reflecting material 41,and is the viscosity before settling the second reflecting material 41in the second resin by a centrifugal force as described later.

Examples of reflecting materials employed for the first reflectingmaterial 31 and the second reflecting material 41 include titaniumoxide, silica, silicon oxide, aluminum oxide, zirconium oxide, magnesiumoxide, potassium titanate, zinc oxide, boron nitride, and the like.Among such examples, titanium oxide, which has a relatively highrefractive index is preferably used from the perspective of lightreflection.

The first reflecting material 31 and the second reflecting material 41may be formed using the same type or different types of materials.

For the second reflecting material 41, one having a larger specificgravity than that of the resin material employed for the second resin ispreferably used. The difference in specific gravity between the secondreflecting material 41 and the resin material facilitates the settlingof the second reflecting material 41 towards the bottom surface by acentrifugal force. Moreover, employing one having a large particle sizefor the second reflecting material 41 can more quickly settle the secondreflecting material 41 towards the bottom surface.

The use of a centrifugal force allows the second reflecting material 41to be disposed with high density, which reduces the space betweenparticles thereby reducing leakage or transmission of light andincreasing the reflectance of the second reflecting layer 40.

The particle size of the second reflecting material 41 preferably is inthe range of from 0.1 μm to 1.0 μm. Having a particle size of 0.1 μm orlarger facilitates the settling of the second reflecting material 41 bya centrifugal force. Having a particle size of 1.0 μm at mostfacilitates the reflection of visible light by the second reflectingmaterial 41. More preferably, the particle size of the second reflectingmaterial 41, is in the range of from 0.4 μm to 0.6 μm from theperspective above description.

The phosphor-containing layer 50 is formed using a third resin thatcontains a phosphor 51. The phosphor-containing layer 50 is disposed onthe second reflecting layer 40 and the light emitting element 20 so asto be in contact with the first reflecting layer 30.

Examples of resin materials employed for the third resin includethermosetting resins, such as an epoxy resin, modified epoxy resin,silicone resin, modified silicone resin, and the like. The resinmaterial used as the third resin may be formed using the same materialas those of the first resin and the second resin, or a differentmaterial. Alternatively, a highly heat resistant resin can be used forthe first resin and the second resin while employing a hard resin forthe third resin.

Silicone resins are generally more resistant to light in the range offrom around 450 nm to around 500 nm than epoxy resins. Epoxy resins areharder than silicone resins. For such reasons, a silicone resin may beused for the first resin and the second resin, and an epoxy resin forthe third resin.

The phosphor 51 is disposed on the upper surface of the light emittingelement 20, the inner lateral surface of the first reflecting layer 30,and the upper surface of the second reflecting layer 40. By disposingthe phosphor 51 on the upper surface of the light emitting element 20,the wavelength of the light from the light emitting element 20 can beefficiently converted before being externally output. By disposing thephosphor 51 on the inner lateral surface of the first reflecting layer30, the wavelength of the light reflected by the first reflecting layer30 can be efficiently converted before being externally output. Bydisposing the phosphor 51 on the upper surface of the second reflectinglayer 40, the wavelength of the light reflected by the second reflectinglayer 40 can be efficiently converted before being externally output.

For the phosphor 51, one having a larger specific gravity than that ofthe resin material employed for the third resin is preferably used. Thisallows the phosphor 51 to naturally settle in the third resin towardsthe bottom surface in the recess 51. The phosphor 51 may be artificiallysettled in the third resin by applying a centrifugal force.

The particle size of the phosphor 51 is in the range of, for example,from 3 μm to 50 μm.

The phosphor 51 may be dispersed in the third resin. Dispersing thephosphor 51 in the third resin can reduce variability in thedistribution of the light exiting from the light emitting device 100.

For the phosphor 51, materials known in the art can be used. Specificexamples include: yellow-emitting phosphors, such as YAG (Y₃Al₅O₁₂:Ce),silicate; red-emitting phosphors, such as CASN (CaAlSiN₃:Eu), KSF(K₂SiF₆:Mn); or green-emitting phosphors, such as chlorosilicate,BaSiO₄:Eu²⁺.

Operation of Light Emitting Device

When the light emitting device 100 is operated, an electric current issupplied to the light emitting element 20 from an external power sourcethrough the first wiring portions 3, the vias 4, the second wiringportions 5, and the third wiring portions 6, resulting in light emissionof the light emitting element 20. Among portions of the light from theemitting element 20, the light L₁ advancing upwards is extracted fromthe upper portion of the light emitting device 100. The light L2advancing downwards is reflected by the reflecting-material-containinglayer 40 a and output towards the opening of the recess 15 to beextracted from the light emitting device 100. The laterally advancinglight L₃ is reflected by the first reflecting layer 30 and outputtowards the opening of the recess 15 to be extracted from the lightemitting device 100. Accordingly, the light emitted from the lightemitting element 20 is less likely to leak from the bottom surface andthe lateral surfaces in the recess 15, thereby improving the lightextraction efficiency. This can also attenuate color non-uniformity.

Method of Manufacturing a Light Emitting Device 100

Next, an example of the method of manufacturing a light emitting deviceaccording to one embodiment will be explained.

FIG. 2 is a flowchart of the method of manufacturing the light emittingdevice according to the embodiment. FIG. 3A is a cross-sectionalillustration of a step of mounting a light emitting element in themethod of manufacturing the light emitting device according to theembodiment. FIG. 3B is a cross-sectional illustration of a step offorming a first reflecting layer in the method of manufacturing thelight emitting device according to the embodiment. FIG. 3C is schematictop-view illustration of the step of forming the first reflecting layerin the method of manufacturing the light emitting device according tothe embodiment. FIG. 3D is a schematic diagram showing a step of forminga second reflecting layer in the method of manufacturing the lightemitting device according to the embodiment, which schematically showsthe application of a centrifugal force to settle the second reflectingmaterial in a second resin that covers the bottom surface in the recessof the package. FIG. 3E is a cross-sectional illustration of a step offorming the second reflecting layer in the method of manufacturing thelight emitting device according to the embodiment, which shows the stateafter settling the second reflecting material by a centrifugal force.FIG. 3F is a cross-sectional illustration of a step of disposing aphosphor-containing layer in the method of manufacturing the lightemitting device according to the embodiment.

The method of manufacturing a light emitting device 100 includes thestep S101 of mounting the light emitting element, the step S102 offorming the first reflecting layer, step S103 of providing the secondresin, the step S104 of forming the second reflecting layer, and thestep S105 of disposing the phosphor-containing layer. The materials andthe layout of the members are as explained with reference to the lightemitting device 100 above, for which the explanation will be omitted asappropriate.

Step of Mounting Light Emitting Element

In the step S101, the light emitting element 20 is mounted on the bottomsurface in the recess 15 formed in the package 10.

The light emitting element 20 is flip-chip mounted substantially in thecenter of the bottom surface in the recess with the surface havingelectrodes serving as the mounting surface. The light emitting element20 is mounted using a conductive adhesive. For the conductive adhesive,for example, eutectic solder, conductive paste, bumps, and the like canbe used. The light emitting element 20 may be mounted with facing up,and in this case, a non-conductive adhesive may be used.

Step of Forming First Reflecting Layer

In the step S102, the first reflecting layer 30 is formed to cover thelateral surfaces in the recess 15 with a first resin containing a firstreflecting material 31.

The first resin that covers the lateral surfaces in the recess 15 isdisposed by, for example, potting. The first resin can be disposed inthe recess 15 by discharging an uncured resin material from the nozzleof a resin discharging device filled with a first resin into thevicinity of the outer edges of the bottom surface in the recess 15(preferably along the borders with the lateral surfaces). The uncuredfirst resin wets and spreads onto the lateral surfaces in the recess 15covering the lateral surfaces in the recess 15. The first resin alsoflows to the bottom surface in the recess 15 at this time, thus thefirst resin covers portions of the outer peripheral regions of thebottom surface in the recess 15. In the present embodiment, theviscosity and the forming positions of the first resin are preferablyadjusted such that the first resin is positioned away from the lateralsurfaces of the light emitting element 20 and creeps up the lateralsurfaces in the recess 15. In the case of forming the first reflectinglayer 30 by potting, the viscosity of the first resin is adjusted to,for example, 1 Pa·s to 50 Pa·s at room temperature (20±5° C.).

In step S102, the interior surfaces of the recess 15 can be pre-wettedwith an organic solvent. By pre-wetting the interior surfaces of therecess 15 with an organic solvent can facilitate the creeping of thefirst resin onto the lateral surfaces of the recess 15. The creeping ofthe resin onto the lateral surfaces of the recess 15 can also befacilitated by using a material having high wettability for the lateralsurfaces of the recess 15, roughening the surfaces of the lateralsurfaces, or other manner.

The first reflecting material 31 is mixed into the first resin beforebeing cured, and the content of the first reflecting material 31 in thefirst resin is preferably set to 10 mass percent to 50 mass percent.

The first resin can wet and spread onto the lateral surfaces of therecess 15 by potting the first resin in the vicinity of the outer edgesof the bottom surface in the recess 15. At this time, the firstreflecting layer 30 is in the state where the first reflecting material31 is dispersed in the first resin.

Subsequently, the first reflecting layer 30 is formed by curing thefirst resin at a temperature, for example, of from 120° C. to 200° C.The first resin is preferably cured in the state where the package isleft standing after allowing the first resin to wet and spread over thelateral surfaces of the recess 15.

In the step 102, the first reflecting member 30 is formed so as to havean inner periphery with a circular shape in a top view.

Step of Providing Second Resin

The step S103 of providing the second resin is the step of mixing thebase resin of a two-component curable resin material and a secondreflecting material 41, followed by mixing a curing agent a certain timeperiod.

Using a second resin provided in this manner can improve the affinitybetween the second reflecting material 41 and the resin material,facilitating the settling of the second reflecting material 41 with acentrifugal force. The temperature before mixing a curing agent isaround room temperature.

Examples of two-component curable resin materials include siliconeresins, modified silicone resins, epoxy resins, modified epoxy resins,and the like.

The time allowed to elapse after mixing the base resin of thetwo-component curable resin materials and the second reflecting material41 is preferably at least 2 hours from the perspective of facilitatingthe settling of the second reflecting material 41. It is preferably 8hours at most, moreover, from the perspective of reducing themanufacturing time. After mixing the curing agent, the subsequent stepis carried out before the second resin is cured.

Step of Forming Second Reflecting Layer

In the step S104, the second reflecting layer 40 is formed by coveringthe bottom surface in the recess 15 with a second resin that contains asecond reflecting material 41 so as to be in contact with the firstreflecting layer 30.

The second resin is disposed, for example, by potting the uncured secondresin on the bottom surface in the recess 15 similar to the first resin.At this time, the second resin is disposed on the bottom surface in therecess 15 while being between the lateral surfaces in the recess 15 andthe light emitting element 20. Preferably, the second resin is disposedin contact with the first reflecting layer 30. This can reduce the flowof the second resin towards the light emitting element 20 to therebymore effectively discourage or prevent the second resin from creepingonto the lateral surfaces of the light emitting element 20 prior tobeing rotated with a centrifugal force. The creeping up of the secondresin onto the lateral surfaces of the light emitting element 20 can beeliminated by changing the shape of the second resin by centrifugalrotation, but the second resin might remain on the lateral surfaces ofthe light emitting element 20 depending on the viscosity of the secondresin and the rotational speed. For this reason, it is preferable toavoid that the second resin covers the lateral surfaces of the lightemitting element 20 before being rotated by a centrifugal force.

Subsequently, the package 10 is rotated in the direction that applies acentrifugal force to the bottom surface in the recess 15. The secondresin moves to the surface close to the bottom surface in the recess 15by this centrifugal force to thereby cover the bottom surface in therecess 15. At this time, even if the second resin covers portions of thelateral surfaces of the light emitting element 20, applying thecentrifugal force can discourage or prevent the wetting and spreading ofthe resin in the height direction of the lateral surfaces of the lightemitting element 20. Furthermore, this centrifugal force can be used forartificially settling the second reflecting material 41 in the secondresin towards the bottom surface in the recess 15, to thereby form alight-transmissive layer 40 b and a layer 40 a that contains the secondreflecting material 41.

The package 10 is preferably rotated by applying a centrifugal force tothe package 10 about an axis of rotation 80 in which the bottom surfacein the recess 15 is positioned outside with respect to the axis.Specifically, the package 10 is moved in a direction A and revolvesabout the axis of rotation 80 such that the axis of rotation 80 ispositioned close to the upper surface side of the package 10. Adirection B in FIG. 3C is a direction parallel to the bottom surface inthe recess 15. The axis of rotation 80 is parallel to the bottom surfacein the recess 15 located on a perpendicular line that passes throughsubstantially the center of the bottom surface in the recess 15, and islocated on the opening side in the recess 15 of the package 10. Thisallows the centrifugal force to act in the direction toward the bottomsurface in the recess 15, to thereby reduce the spreading of the secondresin in the height direction of the package 10 and artificially settlethe second reflecting material 41 towards the bottom surface in therecess 15 (in the direction C in FIG. 3D). By curing the second resin inthis condition, the layer 40 a containing the second reflecting material41 and the light-transmissive layer 40 b are formed on the bottomsurface in the recess 15 in that order.

For the second reflecting layer 40 can be formed by suitably adjustingthe discharging amount and the content of the second reflecting material41 in the second resin. Then the second reflecting layer 40 is formedsuch that the reflecting-material-containing layer 40 a does not face atleast some portions of the lateral surfaces of the light emittingelement 20.

The rotational speed or number of revolutions when applying acentrifugal force to the package 10 would depend on the content andparticle size of the reflecting material 41, but the number of rotationsand the turning radius of the rotation can simply be adjusted such thata centrifugal force of, for example, 200×g will be applied.

In the manufacturing process, when rotating multiple packages 10configuring as a substrate block before being divided into individualsubstrates, the larger the area of the substrate block, (more precisely,the longer the length of the substrate in the direction of rotation A),the packages 10 positioned at a greater distance from the center of thesubstrate block will be deviated from the axis of rotation 80. In thesubstrate block, for example, when the deviations from the circumferenceof revolution in the direction B increase, the second resin surfacesbecome inclined to the bottom surfaces in the recesses 15, possiblyresulting in variability in the surface condition of the second resinsin the packages on the substrate block. These deviations can be reducedby increasing the turning radius. Specifically, using a turning radiusat least 70 times the length of the substrate block arranged along thedirection of rotation can reduce the deviations.

In the case of employing flexible resin packages 10 in which thesubstrate block warps along the circumference of the turning radius, theaforementioned deviations are less likely to occur. Accordingly,rotation can be performed with a larger substrate block than in the caseof employing a substrate block composed of non-flexible packages 10.This can increase the number of packages processed at a time.

In step S104, the second resin is preferably cured while settling thesecond reflecting material 41. It is preferable to use a secondreflecting material 41 having a small particle size from the perspectiveof reflection, but because smaller particles cannot be readily settled,the second reflecting material 41 is artificially settled towards thebottom surface in the recess 15 by using a centrifugal force in thisprocess. In order to cure the resin in the state where the secondreflecting material 41 is settled, it is preferable to cure the secondresin under rotation, in other words, while rotating the packages, inthis process.

It is possible to cure the resin after the rotation has ceased, but oncethe rotation ceases the wettability of the resin causes the resin toreadily spread over the lateral surfaces of the light emitting element20. Curing the second resin while rotating the package 10 can thusdiscourage or prevent the second resin from creeping onto the lateralsurfaces of the light emitting element 20. Exposure of the lateralsurfaces of the light emitting element 20 from the second resin canfurther increase the light extraction efficiency, and further improvecolor distribution of light emitted from the light emitting device 100.

The curing temperature for the second resin at this time can be in therange of from 40° C. to 200° C. Increasing the curing temperature canreduce the time required for curing the second resin, and is thusefficient. Considering the wobbling of the axis of the rotation 80 dueto thermal expansion generated at the metal parts in the equipment forcentrifugal rotation, the curing temperature is preferably as low aspossible. That is, the curing temperature for the second resin ispreferably 50° C. or higher from the perspective of efficiency. Thecuring temperature for the second resin is preferably 60° C. at mostconsidering the wobbling of the axis of rotation 80. When curing theresin at a temperature of 80° C. or higher, it is preferable to adjustthe equipment for centrifugal rotation such that at least the metalparts of the equipment for centrifugal rotation would not reach 80° C.or higher.

The resin material that composes the second resin is preferably selectedfrom among those that can achieve at least a semi-cured condition whenthe rotating package 10 is maintained at 40° C. or higher.

Examples of methods for curing the second resin while allowing thesecond reflecting material 41 to settle include blowing of a hot air,using a panel heater, or the like.

Step of Disposing Phosphor-Containing Layer

In the step S105, the phosphor-containing layer 50 in which a thirdresin contains a phosphor 51 on the second reflecting layer 40 and thelight emitting element 20.

The third resin is disposed in the recess 15 by potting, spraying, orthe like. The phosphor 51 naturally settles in the third resin, and isdisposed on or above the upper surface of the light emitting element 20,the inner surface of the first reflecting layer 30, and the uppersurface of the second reflecting layer 40. Subsequently, the third resinis cured at a temperature of, for example, from 120° C. to 200° C. toform the phosphor-containing layer 50.

The method of manufacturing the light emitting device, and the lightemitting device, according to the embodiments of the present disclosurehave been explained above based on specific embodiments, but the scopeand spirit of the present invention are not limited to those disclosedabove, and must be broadly interpreted based on the scope of the claimsdisclosed herein. Those altered or modified in various ways based on thepresent disclosure are also encompassed by the scope and spirit of thepresent invention.

OTHER EMBODIMENT

FIG. 4 is a schematic cross-sectional view of the structure of a lightemitting device according to another embodiment. FIG. 5 is a schematiccross-sectional view of the structure of a light emitting deviceaccording to still another embodiment. FIG. 6 is a schematiccross-sectional view of the structure of a light emitting deviceaccording to still another embodiment. FIG. 7A is a schematicperspective view of the structure of a light emitting device accordingto still another embodiment. FIG. 7B is a schematic cross-sectional viewtaken along line VIIB-VIIB in FIG. 7A. FIG. 8A is a schematic top viewof a light emitting device according to still another embodiment. FIG.8B is a schematic cross-sectional view taken along line VIIIB-VIIIB inFIG. 8A. FIG. 8C is a schematic cross-sectional vies taken along lineVIIIC-VIIIC in FIG. 8A. FIG. 9A is a schematic top view of a lightemitting device according to still another embodiment. FIG. 9B is aschematic cross-sectional view taken along line IXB-IXB in FIG. 9A.

The light emitting device 100A shown in FIG. 4 includes bumps 60provided between the light emitting element 20 and the bottom surface inthe recess 15. In the light emitting device 100A, the light emittingelement 20 is mounted on the bottom surface in the recess 15 via thebumps 60. The bumps 60 raise the light emitting element 20 in the heightdirection of the light emitting element 20. The second reflecting layer40 is disposed such that the layer 40 a containing the second reflectingmaterial 41 does not face the lateral surfaces of the light emittingelement 20. The second reflecting layer 40 is disposed such that thesemiconductor layer 22 of the light emitting element 20 does not facethe reflecting-material-containing layer 40 a.

Such a structure can reduce loss of primary light caused by that theprimary light is reflected at the lateral surfaces of the light emittingelement 20. Increasing the primary light extracted from the lateralsurfaces of the light emitting element 20 can reduce multipleexcitations of the phosphor 51, thereby further improving the colordistribution of light emitted from the light emitting device 100A.

For the bumps 60, for example, Au bumps can be used.

The light emitting device 100B shown in FIG. 5 has posts 70 disposedbetween the light emitting element 20 and the bottom surface in therecess 15. In the light emitting device 100B, the light emitting element20 is mounted on the bottom surface in the recess 15 via the posts 70.The posts 70 raise the light emitting element 20 in the height directionof the light emitting element 20. The second reflecting layer 40 isdisposed such that the layer 40 a containing the second reflectingmaterial 41 does not face the lateral surfaces of the light emittingelement 20. The second reflecting layer 40 is disposed such that thesemiconductor layer 22 of the light emitting element 20 does not facethe reflecting-material-containing layer 40 a.

Such a structure can reduce loss of primary light caused by that theprimary light is reflected at the lateral surfaces of the light emittingelement 20. Increasing the primary light extracted from the lateralsurfaces of the light emitting element 20 can reduce multipleexcitations of the phosphor 51, thereby further improving the colordistribution of light emitted from the light emitting device 100B.

For the posts 70, for example, Cu posts can be used.

In the light emitting device 100C shown in FIG. 6, the second reflectinglayer 40 has a concave surface at the opening side. Such a surfacecondition can be achieved by reducing the rotational speed applied tothe package 10. The second reflecting layer 40 may include substantiallyno light-transmissive layer 40 b. Even in this case, by curing thesecond resin under rotation, in other words, under a centrifugal force,the shape of the second resin can be changed so as to cover the entirebottom surface in the recess 15 exposed from the first reflecting layer30 while reducing the creeping up of the second reflecting layer 40 ontothe lateral surfaces of the light emitting element 20.

Such a structure can reduce loss of primary light caused by that theprimary light is reflected at the lateral surfaces of the light emittingelement 20. Increasing the primary light extracted from the lateralsurfaces of the light emitting element 20 can reduce multipleexcitations of the phosphor 51, thereby further improving the colordistribution of light emitted from the light emitting device 100C.

The light emitting device 100D shown in FIGS. 7A and 7B is a device inwhich the light emitting element 20 is face-up mounted on the bottomsurface in the recess 15 of the package 10A. The light emitting element20 is mounted on the second lead 3 b. In the present embodiment, theN-side electrode of the light emitting element 20 is connected to afirst lead 3 a via a wire 23, and the P-side electrode is connected to asecond lead 3 b via a wire 24.

By mounting the light emitting element 20 with facing up, thesemiconductor layer 22 of the light emitting element 20 can bepositioned at the light extraction surface side such that thesemiconductor layer 22 does not face the reflecting-material-containinglayer 40 a.

Such a structure can reduce loss of primary light caused by that theprimary light is reflected by the lateral surfaces of the light emittingelement 20. Increasing the primary light extracted from the lateralsurfaces of the light emitting element 20 can reduce multipleexcitations of the phosphor 51, thereby further improving colordistribution of light emitted from the light emitting device 100D.

A light emitting device 100E shown in FIGS. 8A, 8B and 8C has arectangular shape in a top view, and defines a recess 15 having arectangular shape in a top view. That is, the package 10B has lateralsurfaces opposing each other in the X direction and other lateralsurfaces opposing each other in the Y direction, which is perpendicularto the X direction. A distance between the lateral surfaces opposingeach other in the X direction is different from a distance between thelateral surfaces opposing each other in the Y direction. The“rectangular shape” herein includes a shape in which one or more cornersare removed, a shape in which one or more corners are rounded, or asubstantially rectangular shape. The structure or constituent members ofthe package 10B are substantially conform to those of the package 10A,therefore the description thereof will not be repeated. In FIG. 8A,curved portions 32 of a first reflecting layer 30 are indicated bydashed lines, and curved portions of a second reflecting layer 40 areindicated by solid lines.

A light emitting element 20 is mounted in the center of the bottomsurface in the recess 15. With this structure of the light emittingdevice 100E, distances between the light emitting element 20 and thelateral surfaces facing in the X direction in the recess 15 is differentfrom distances between the light emitting element 20 and the lateralsurfaces facing in the Y direction in the recess 15. That is, in thelight emitting device 100E, a distance between the lateral surface ofthe light emitting element 20 and the lateral surface in the recess 15in the longitudinal direction of the package 10B is different from adistance between the lateral surface of the light emitting element 20and the lateral surface in the recess 15 in the width direction of thepackage 10B. In the present embodiment, the distances between thelateral surfaces of the light emitting element 20 and the lateralsurfaces in the recess 15 is made different by the recess 15 to have therectangular shape in a top view. However, the distances thereof may bemade different by the light emitting element 20 to have a rectangularshape. As described above, the package 10B or the light emitting element20 may be formed such that a distance between one of the lateralsurfaces of the light emitting element 20 and one of the lateralsurfaces in the recess 15 in the X direction is different from adistance between the other one of the lateral surfaces of the lightemitting element 20 and the other one of the lateral surfaces in therecess 15 in the Y direction.

The first reflecting layer 30 has curved portions 32 each having aconcave shape toward the light emitting element 20. The curved portions32 extend in the X direction in a top view. The first reflecting layer30 defines a gap 33 such that at least a portion of the lateral surfacesin the recess 15 faces the light emitting element 20 in the Y direction.

The curved portions 32 of the first reflecting layer 30 are positionedopposite sides of the package 10B in the X direction in a top view, inother words, one side (i.e., left side of the drawing) and the otherside (i.e., right side of the drawing) of the package 10B. With thisstructure, the first reflecting layer 30 covers the shorter lateralsurfaces in the recess 15. The covered portions 32 are formed such thatits concave portions respectively face substantially the center of thelateral surfaces of the light emitting element 20. Specifically, thedeepest portion of the concaved portion of each of the concaved portions23 faces substantially the center of the corresponding lateral surfaceof the light emitting element 20.

Portions of the gap 33 of the first reflecting layer 30 positioned atone side (i.e., upper side of the drawing) and the other side (i.e.,lower side of the drawing) in the Y direction are defined such thatsubstantially no first reflecting layer 30 is provided at the portionswhere the light emitting element 20 faces. Specifically, ends 32 a ofeach of the curved portions 32 are positioned on or outward of theextended line of the corresponding lateral surfaces of the lightemitting element 20. Each of the lateral surface facing in the Ydirection in the recess 15 has a portion that faces the light emittingelement 20. Such portion of each of the lateral surfaces in the recess15 faces the phosphor-containing layer 50, but not faces the firstreflecting layer 30.

With such a structure, substantially no first reflecting layer 30 isprovided on the portion of the lateral surface in the recess 15 facingin the Y direction with which a distance from the lateral surface of thelight emitting element 20 is shorter. Thus substantially no part of thesecond reflecting layer 40 overlaps the first reflecting layer 30.Accordingly, the surface of the second reflecting layer 40 extending inthe Y direction can be good flatness. This surface flatness, forexample, allows the layer configuring the settled phosphor 51 to be goodflatness after settling the phosphor 51 in the third resin. In the casein which the distance between the light emitting element 20 and thefirst reflecting layer 30 is short, and the second reflecting layer 40overlaps the first reflecting layer 30, the phosphor 51 adjacent to thelateral surfaces of the light emitting element 20 possibly be disposedat a position higher than the light emitting element 20. This mayincrease ratio of the secondary light that is light converted by thephosphor 51, possibly result in color non-uniformity in the emittedlight.

That is, a certain distance or more can be secured between the outerperiphery of the light emitting element 20 and the first reflectinglayer 30 (or the lateral surfaces on which substantially no firstreflecting layer 30 is provided in the recess 15), to thereby making thesecond reflecting layer 40 flat at the outer periphery and its vicinityof the light emitting element 20. Thus, the phosphor-containing layer 50may be positioned at the lower area on the second reflecting layer 40 ina top view. This can improve the light distribution and colordistribution of light emitted from the light emitting device 100E. Fromthe perspective of the above description, the distance between the lightemitting element 20 and the first reflecting layer 30 in a top view ispreferably at least 100 μm, more preferably at least 300 μm. From theperspective of facilitating the second reflecting layer 20, the distancebetween the light emitting element 20 and the first reflecting layer 30is preferably 1500 μm or less.

The state of the first reflecting layer 30 may be controlled byadjusting the discharging amount of the first resin containing the firstreflecting material 31, the position where the first resin isdischarged, or the amount of the first reflecting material 31 containedin the first resin. Amount adjustment of the first reflecting material31 contained in the first resin can be achieved by, for example, addingAerosil® of at least 2.0 parts by mass and 6.5 parts by mass at mostrelative to 100 parts by mass of the first resin.

In the present embodiment, the first reflecting layer 30 defines the gap33 at the lateral surfaces facing in the Y direction in the recess 15,and is absent on portions that face the light emitting element 20.However, the first reflecting layer 30 may be absent only on portions ofthe lateral surfaces facing in the Y direction in the recess 15 thatface the light emitting element 20. As well as portions of the lateralsurfaces in the recess 15 that face the light emitting element 20 in theY direction, the first reflecting layer 30 may be absent on portions ofthe lateral surfaces in the recess 15 that do not face the lightemitting element 20. The gap 33 may be adjusted by changing thepositions of the ends 32 a of the curved portions 32 along the lateralsurfaces facing in the Y direction in the recess 15.

The light emitting device 100E includes a protection device 90. Theprotection device 90 may be, for example, Zener diode.

The light emitting device 100F shown in FIGS. 9A and 9B has arectangular shape in a top view, and defines a recess 15 having arectangular shape in a top view. The package 10C includes a supportmember 2 b, a pair of first lead 3 c and a second lead 3 d. The supportmember 2 b supports the first lead 3 c and the second lead 3 d at apredetermined position. The support member 2 d may be formed using, forexample, the same material of the insulating substrate 2 of the lightemitting device 100. The first lead 3 c and the second lead 3 d may beformed using, for example, the same material of the first wiringportions 3 in the light emitting device 100. FIG. 9A is a diagram seeingthrough the second reflecting layer 40, and a curved portion 32 of afirst reflecting layer 30 is indicated by solid lines.

The light emitting element 20 is disposed on a portion of the bottomsurface where is shifted to one side from the center in the recess 15.In the present disclosure, the light emitting element 20 is disposed ata position shifted from the center of the bottom surface in the recess15 to one side in the X direction (e.g., left side in FIG. 9A) and toone side in the Y direction perpendicular to the X direction (e.g.,lower side in FIG. 9A). Specifically, the light emitting element 20 isdisposed on the first lead 3 c while being positioned at an obliquelydownward to the left from the center in the recess 15 in the drawing.

The first reflecting layer 30 defines the curved portion 32 being curvedfrom one lateral surface extending in one direction toward other lateralsurface facing the one lateral surface in the recess 15 in a top view.Specifically, the curved portion 32 of the first reflecting layer 30 arecurved form one lateral surface extending in the X direction towardother lateral surface facing the one lateral surface (i.e., right sidein FIG. 9A) in the recess 15 in a top view. That is, the curve of thecurved portion 32 start from one lateral surface toward other lateralsurface facing in the Y direction in order to have a concave shapetoward the light emitting element 20 in the X direction in a top view.With this structure, the first reflecting layer 30 covers theaforementioned other lateral surface that is one of the shorter lateralsurfaces in the recess 15. One of the ends 32 a of the curved portion 32is located at a position on one side where the light emitting element 20face in the Y direction. The other one of the ends 32 a of the curvedportion 32 is not located at a position of the other side where thelight emitting element 20 faces in the Y direction. Thus, the firstreflecting layer 30 is disposed on the lateral surfaces in the recess 15so as to face most part of adjacent two lateral surfaces of the lightemitting element 20, and to not face the other two of adjacent lateralsurfaces of the light emitting element 20. The deepest portion of thecurved portion 32 faces the light emitting element 20.

The ends 32 a of the curved portion 32 extends toward portions of thelateral surfaces facing each other in the Y direction in the recess 15.Specifically, in the recess 15, one of the ends 32 a on the lateralsurface (e.g., upper side in FIG. 9A) is located in a position closer toone of the lateral surfaces facing in the X direction than the other oneof the ends 32 a on the lateral surface (e.g., lower side in FIG. 9A)facing the aforementioned lateral surface in the Y direction.Accordingly, the curved portion 32 can be formed such that the deepestportion of the curve faces the light emitting element 20.

With this structure, in regard to the lateral surfaces facing each otherin the X direction in the recess 15, a relatively long distance can beensured from one lateral surface of the light emitting element 20 facingthe deepest portion of the curved portion to the one lateral surface ofthe first reflecting layer 30, thereby improving color distribution oflight emitted from the light emitting device 100F.

The state of the first reflecting layer 30 may be controlled byadjusting the discharging amount of the first resin containing the firstreflecting material 31, the position where the first resin isdischarged, or the amount of the first reflecting material 31 containedin the first resin. When the discharging position is adjusted, the firstresin is preferably discharged at a discharging position 16.

In the light emitting device 100E shown in FIG. 8A, 8B, 8C or the lightemitting device 100F shown in FIG. 9A, 9B, the curved portion 32 mayhave a large or small curvature radius. The curved portion 32 may be aportion of a circular arc. The deepest portion of the curved portion 32may appropriately be shifted in the X or Y direction.

The method of manufacturing a light emitting device may include anotherstep between the steps described above or before or after the stepsdescribed above to the extent it does not adversely affect the stepsdescribed above. For example, a step of removing foreign substancesmixed in during the manufacturing process, or the like, can be included.

In the method of manufacturing a light emitting device, moreover, somesteps are not restricted by the order in which they are performed, andmay be performed in reverse order. For example, the step of mounting thelight emitting element may be performed after the step of forming thefirst reflecting layer.

Furthermore, in the method of manufacturing a light emitting devicedescribed above, the step of providing the second resin followed by thestep of forming the first reflecting layer, but the step of providingthe second resin may be performed between the step of mounting the lightemitting element and the step of forming the first reflecting layer, orbefore the step of mounting the light emitting element. The method doesnot have to include the step of providing the second resin.

What is claimed is:
 1. A method of manufacturing a light emittingdevice, the method comprising: mounting a light emitting element in apackage in which a recess is defined, the light emitting element beingmounted on a bottom surface defining the recess; forming a firstreflecting layer by covering lateral surfaces defining the recess with afirst resin containing a first reflecting material; forming a secondreflecting layer covering the bottom surface defining the recess, suchthat the second reflecting layer is in contact with the first reflectinglayer, wherein the step of forming the second reflecting layer comprisessettling the second reflecting material in the second resin by acentrifugal force so as to form (i) a layer containing a secondreflecting material on the bottom surface defining the recess, and (ii)a light-transmissive layer above the layer containing the secondreflecting material, and wherein at least a portion of a lateral surfaceof the light emitting element is not covered by the layer containing thesecond reflecting material; and disposing a phosphor-containing layer onthe second reflecting layer and the light emitting element, thephosphor-containing layer comprising a third resin that contains aphosphor.
 2. The method of manufacturing a light emitting deviceaccording to claim 1, wherein the second reflecting material is settledby applying a centrifugal force to the package about an axis of rotationsuch that the bottom surface defining the recess is positioned outwardof the axis of rotation.
 3. The method of manufacturing a light emittingdevice according to claim 1, wherein the step of forming the secondreflecting layer comprises curing the second resin while settling thesecond reflecting material.
 4. The method of manufacturing a lightemitting device according to claim 3, wherein the second resin is curedat a temperature in a range of 40° C. to 200° C.
 5. The method ofmanufacturing a light emitting device according to claim 1, wherein thesecond reflecting material comprise titanium oxide.
 6. The method ofmanufacturing a light emitting device according to claim 5, wherein aparticle size of the titanium oxide is in a range of 0.1 μm to 1.0 μm.7. The method of manufacturing a light emitting device according toclaim 1, wherein a viscosity of the second resin is in a range of 0.3Pa·s to 15 Pa·s.
 8. The method of manufacturing a light emitting deviceaccording to claim 1, further comprising: before the step of forming thesecond reflecting layer, forming the second resin containing a secondreflecting material by performing steps comprising: mixing a base resinof a curable resin material and the second reflecting material to form amixture, and after allowing at least two hours to elapse, mixing acuring agent into the mixture.
 9. A method of manufacturing a lightemitting device, the method comprising: mounting a light emittingelement in a package in which a recess is defined, the light emittingelement being mounted on a bottom surface defining the recess; forming afirst reflecting layer by covering lateral surfaces defining the recesswith a first resin containing a first reflecting material; forming asecond reflecting layer by covering the bottom surface defining therecess with a second resin containing a second reflecting material, suchthat the second reflecting layer is in contact with the first reflectinglayer, wherein the step of forming the second reflecting layercomprises: disposing the second resin on the bottom surface in therecess at a position between the lateral surfaces of the recess and thelight emitting element, by potting, applying a centrifugal force to thepackage about an axis of rotation such that the bottom surface definingthe recess is positioned outward of the axis of rotation, so as tochange a shape of the second resin such that the second resin covers anentirety of the bottom surface defining the recess that is exposed fromthe first reflecting layer, and curing the second resin while applyingthe centrifugal force; disposing a phosphor-containing layer on thesecond reflecting layer and the light emitting element, thephosphor-containing layer comprising a third resin that contains aphosphor.
 10. The method of manufacturing a light emitting deviceaccording to claim 9, wherein the second resin is cured at a temperaturein a range of 40° C. to 200° C.
 11. The method of manufacturing a lightemitting device according to claim 9, wherein the second reflectingmaterial comprise titanium oxide.
 12. The method of manufacturing alight emitting device according to claim 11, wherein a particle size ofthe titanium oxide is in a range of 0.1 μm to 1.0 μm.
 13. The method ofmanufacturing a light emitting device according to claim 9, wherein aviscosity of the second resin is in a range of 0.3 Pa·s to 15 Pa·s. 14.The method of manufacturing a light emitting device according to claim9, further comprising: before the step of forming the second reflectinglayer, forming the second resin containing a second reflecting materialby performing steps comprising: mixing a base resin of a curable resinmaterial and the second reflecting material to form a mixture, and afterallowing at least two hours to elapse, mixing a curing agent into themixture.
 15. A light emitting device comprising: a package on which arecess is defined; a light emitting element mounted on a bottom surfacedefining the recess; a first reflecting layer covering lateral surfacesdefining the recess, the first reflecting layer comprising a first resinin which a first reflecting member is dispersed; a second reflectinglayer covering the bottom surface defining the recess, wherein thesecond reflecting layer is in contact with the first reflecting layer,wherein the second reflecting layer comprises (i) a layer containing asecond reflecting material on the bottom surface defining the recess,and (ii) a light-transmissive layer above the layer containing thesecond reflecting material, and wherein at least a portion of a lateralsurface of the light emitting element is not covered by the layercontaining the second reflecting material; and a phosphor-containinglayer on the second reflecting layer and the light emitting element, thephosphor-containing layer comprising a third resin that contains aphosphor.
 16. The light emitting device according to claim 15, wherein:the lateral surfaces of the recess define a rectangular shape or asquare shape in a top view, two of the lateral surfaces face each otherin an X direction, and the other two of the lateral surfaces face eachother in Y direction that extends in a direction perpendicular to the Xdirection, the first reflecting layer has a curved portion having aconcave shape that faces the light emitting element in the X directionin the top view, and the first reflecting layer defines a gap at whichat least a portion of the two lateral surfaces that face each other inthe Y direction face the light emitting element.
 17. The light emittingdevice according to claim 16, wherein: the light emitting element isdisposed at a center of the bottom surface defining the recess in thetop view, a distance between the light emitting element and the lateralsurfaces facing in the X direction in the recess is different from adistance between the light emitting element and the lateral surfacesfacing in the Y direction in the recess.
 18. The light emitting deviceaccording to claim 15, wherein the light emitting element is disposed ata position shifted from a center of the bottom surface defining therecess to one side in the recess in the top view, the curved portion iscurved from a first of the two lateral surfaces that face each other inthe Y direction toward a second of the two lateral surfaces that faceeach other in the Y direction in a top view, the curved portion isformed such that a deepest portion of the curve faces the light emittingelement.
 19. The light emitting device according to claim 15, whereinthe second reflecting material comprises titanium oxide.
 20. The lightemitting device according to claim 15, wherein the second reflectinglayer has a thickness in a range of 10 μm to 200 μm.